Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

I made a thread in another forum, but thought it would be more appropriate to post it in here. So here goes.

I have been taking this medicine with Concerta for a couple of weeks now, originally the chlorphenamine was used for allergies but I noticed an anxiolytic and antidepressant effect of it. I was also no longer grumpy of a morning, slept better and felt generally happier. Coupled with the typical, antidepressant side effects of increased sweating, dry mouth and some digestive complaints for a short while, I felt confident it was somewhat acting like an antidepressant. I researched and then explained this to my psychiatrist and he agreed with me, asking for me to email him the literature I've been reading. He also prescribed me long-action (12-hour) chlorphenamine on the basis it seems to be helping. My psychiatrist had told me that during the pre-stimulant era, they used various antihistamines, including chlorphenamine for those with ADHD to calm them down.

The research I conducted brought up the following information, which I have based my conclusions on.

Take a peak at the following image, the structures of methylphenidate and chlorphenamine are distantly similar. But compared to the antidepressant zimelidine, chlorphenamine is extremely similar:

The first marketed SSRI was zimelidine, which was based off the structure of chlorphenamine and brompheniramine. By the time the neurological effects of chlorphenamine had been noticed, the drug had gone off-patent, and there was no more money to be made besides generic formulations. This led to the development of non-sedating, but less effective antihistamines and antidepressants that were little to no more effective than chlorphenamine.

There is also some possible evidence of binding to various receptors (although which receptors and whether they are agonised, antagonised or inversely agonised is not apparent), including D1, α1 and 5-HT. The muscarinic and histamine receptor blockade, plus the inhibition of the monoamine transporters makes it is highly likely that chlorphenamine and its lack of receptor selectivity will cause it to bind to various other receptors similar to the action imipramine and other tricyclics. Though receptor binding and effects are partly speculative from me, based on the evidence I've read.

Although the antihistamine effects of chlorphenamine are believed to only work for roughly 6 hours, the half life of the drug is 21-27 hours, this corresponds with me feeling less anxious, happier, etc. even in the absence of a dose within 6 hours. The therapeutic neurological effects appear to remain beyond the indicated antihistamine effects.

Interestingly, according to http://www.ncbi.nlm.nih.gov/pubmed/16413139. Chlorphenamine "compares favourably with amitriptyline and imipramine with respect to actions on both serotonergic and noradrenergic neurons." and that it "might also be called a selective serotonin and noradrenaline reuptake inhibitor (SSNRI) and be compared with new drugs, such as venlafaxine."
It's possible that a drug as old as chlorphenamine is just as good, and with less side effects than venlafaxine or the tricyclics amitriptyline and imipramine, is available over the counter, for a cheap price, has had information pertaining to it's therapeutic effects withheld in the name of corporate greediness?

This evidence is further strengthened with the warning to not take chlorphenamine with an MAOI within the last 14 days of one another due to a risk of fatal serotonin syndrome.

I don't believe chlorphenamine to be for everyone, nor do I believe it to be as effective in some severe cases of depression in which the likes of mirtazapine (another extremely effective antidepressant, far more effective than SSRIs) and the daddy of all - MAOIs should dominate.

However, if anyone is suffering from anxiety and/or depression, then I'd like to ask is anyone willing to test my success on themselves? If anyone is, please let me know and also make sure you READ THE LABEL for chlorphenamine and do NOT combine it with MAOIs or other antidepressants without first consulting your doctor. Please also be aware that chlorphenamine is an opiate potentiator so opiates become stronger than they normally would.

If anyone has any questions, I'll be more than happy to attempt to answer them.

Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

I'm really intrigued by all of this. I read the intro to the Let Them Eat Prozac book and found that quite fascinating, too.

On top of that, this whole topic is synergistic with my world right now cos I have a cold and was wondering if it was my imagination that my cold medication was improving my mood.

As it turns out, there's no chlorphenamine in it; rather, it's the dextromethorphan (cough suppressant) that's making me feel less depressed. I never knew it was also an SRI! But since the box is almost empty, I think I just might look at chlorphenamine meds when I go back to the drugstore. I'm intrigued by the possibilities!

__________________

Dx: ADD-PI, Double Depression, PTSD
Rx: Dextroamphetamine IR for ADD-PI.
Currently on a trial of Chlorpheniramine for depression & anxiety. So far so good.

Formerly on Wellbutrin, Prozac, and various forms of
Ritalin, Adderall, Vyvanse

Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

Just an FYI: When you buy:Chlorphenamine/chlorpheniramine is typically supplied in 4mg instant release tablets (though there are slow-release varieties at 12mg).Dex-chlorphenamine/dex-chlorpheniramine is typically supplied in 2mg instant release tablets.

You are usually getting both the levo, and dextrorotary isomer of the drug in the racemic 4mg mixture. The dextrorotary isomer is considered to have psychopharmacological effects, while the levorotary version has little to no efficacy. So in a 4mg pill, you effectively get 2mg of the most active drug. This is not a problem, however.

A therapeutic dose seems to be around the range of 12mg to an absolute maximum of 32mg per day (and 6mg - 16mg for dex-chlorphenamine). Lower doses tend to be more sedating, while higher doses tend to be more stimulating.

I would seriously recommend nobody drive or operate machinery, as the label says for a while until you know how this drug will affect you.

Last edited by NotoriousPyro; 12-09-12 at 10:42 PM..

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Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

Interesting. I just bought a pack of 24 4mg tablets and I'm going to try it out. I'll let you know how it goes. Thanks for the info.

__________________
I hate turkeys. If you stand in the meat section at the grocery store long enough, you start to get mad at turkeys. There's turkey ham, turkey bologna, turkey pastrami,...someone needs to tell the turkey, man, just be yourself!
-Mitch Hedberg

My nephew has HDADHD. High Definition Attention Deficit Disorder. He can barely pay attention, but when he does it's unbelievably clear.
-Steven Wright

Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

Been trying this for 6 days so far. So far I can definitely say I have noticed the sedating effects. In fact I am able to treat it like a sleep aid. One 4 mg pill and I am drowsy within 20 minutes. The longer I've gone without sleep, the greater the drowsy effect.

I am not sure about this yet, but it is possible I may be experiencing some slight mood improvement, but I can't be sure yet. Could be placebo, could be some other things.

What dosages do you take, ccrawford? You noted that higher doses are stimulating... what dose do you find stimulating, and what dose improves your mood? And how quickly does it do so?

Any other pointers about when/how to take it? Food/med interactions, etc?

Thanks for all your info so far on this! I'm feeling hopeful about the possibilities.

__________________

Dx: ADD-PI, Double Depression, PTSD
Rx: Dextroamphetamine IR for ADD-PI.
Currently on a trial of Chlorpheniramine for depression & anxiety. So far so good.

Formerly on Wellbutrin, Prozac, and various forms of
Ritalin, Adderall, Vyvanse

The Following User Says Thank You to Phoenix Ash For This Useful Post:

Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

After a while, the direct sleepiness side-effects disappear due to histamine receptor sensitisation. Though it may indirectly improve sleep through anxiolysis and antidepressant effects.

For me, it tends to "stabilise" my mood rather than directly improve it. Such as things not bothering me as much anymore, being less anxious and thus happier because I can be settled, etc. Remember: antidepressants do not make you happy, they simply try to stop you thinking negatively, thus improving your overall mood.

Roughly, I aim for around 4-5 pills per day, at 3-5 hour intervals. This totals to around 20-24mg per day.

I've noticed that I feel less boredom-derived lethargy, anxiety, and my mood seems to be more stable. Combined with Concerta they appear to complement each other. Concerta alone doesn't alleviate my mood swings, it makes my anxiety worse and I get quite lethargic and sick. The comedown from methylphenidate appears to be smoother and less irritable with chlorphenamine too.

Recently, I've been taking a 27mg Concerta tablet at 7am and 3pm, this really improves my mood yet I don't feel the same "overdrive" anxious feelings which I used to feel beyond 27mg. In fact, I've taken far much more than I've ever took and still no anxiety. I used to have to steer away from caffeine while on Concerta as this would make me super-anxious and really jittery, now I can drink what I want and take much more Concerta and experience the positive benefits without the anxiety.

The first day of taking chlorphenamine I noticed the anxiolytic effects, shortly afterwards (3-4 days) my mood started to improve. Whether or not this is related to the anxiolysis, I don't know.

The only interactions with other medications I can explicitly name are the ones I listed:
If you're taking any other antidepressant, first consult your doctor.Do NOT combine with MAOIs, especially irreversible ones.

As far as I'm aware, it doesn't interact with any foods and can be taken with or without food. Alcohol consumption isn't recommended as it increases the sedative effects, though alcohol makes you depressed anyway, so it's probably a good thing that you shouldn't drink it!

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Re: Chlorphenamine (OTC antihistamine) for Anxiety. Research and speculation.

Thank you again for sharing your experience. This is great information!

So far I've only been at 4 mg/day. I'm considering bumping it up soon, to 8 mg.

However, I dislike having to remember to take pills multiple times a day. What made you decide to space them out? Do you think there would be a difference between taking, say, 12 mg chlorpheniramine all at once in the morning vs spaced out in 3 doses over 12 hours? Have you tried anything like that?

__________________

Dx: ADD-PI, Double Depression, PTSD
Rx: Dextroamphetamine IR for ADD-PI.
Currently on a trial of Chlorpheniramine for depression & anxiety. So far so good.

Formerly on Wellbutrin, Prozac, and various forms of
Ritalin, Adderall, Vyvanse

The Following User Says Thank You to Phoenix Ash For This Useful Post: